Governor for pressure-fluid-operated tools



Dec. 24, 1929. E. H. sHAFF GOVERNOR FOR PRESSURE FLUID OPERATED TOOLSFiled Feb. 5,1925 Y Patented Dec. 24, 1929 UNITED STATES PATENT OFFICEERNEST sIAEEoF GRAND vI I'rii'lzirl,iviIcIIIGAN, AssIGNoR To WILLIAM H.KELLER, INCL, 0E GRAND HAVEN, MICHIGAN, A CORPORATION oF' MICHIGANGOVERNOR EoR PRESSURE-FLUID-OPERATED Toons Application filed FebruaryThe invention relates generally to' governors and more particularly toar` governor adapted to be insertedin a handle through Which air passesunder manual control.

It is the general object of the invention to provide an improvedgovernor of the type adapted normally to pass a small quantity ofpressure fluid to a tool when idling, and Which Will automatically passincreasing` quantities of pressure fluid to the tool as the loaden thetool increases.

Another object of the invention is to provide an automatic governor ofthis type adapted to be incorporated in the handle of a tool, thegovernor being adapted to fit detachably Within a handle of a sizereadily gripped in the hand.

Another object of the v invention is to provide such a governor withautomatic valve means adapted to bep'osi'tioned immediately adjacent thetool/endof a handle and as near the load as prac'tical.

Further objects and advantages of the invention will become apparentfrom the following detailed description taken in conneetion With theaccompanying` drawing in which y Figure 1 is an external view of a toolhandle incorporating the preferred form of the invention.

Fig. 2 is a longitudinal central section thereof.

Fig. 3 isl a vie'vv' ofthe manually operable valvemember.

Fig. 4 is an end view thereof.

Fig; 5 is a perspective vievv of a valvel bushing in the governor; Y

Fig. 6' is a'fragmental perspective view of the automatically operablevalve of the governor'.

While my inventionsseeeptibie df ein..

bodiment in many different forms, have Shovvn in' the drawings and` Willherein Ade"- scribe4 in detail one such` embodimentvvith theunderstanding that the" present disclosure isi to" be considered as anex'emplilication ofV the principles ofthe inventi'o and i's not. 'flltoliinit the invention.totheienbodimiit'il strated `'Ihescop Y ofminimisation werbe tue-appended.' en

5,1926. serial No. 86,145.

` Referring` to the drawings, the invention in lthe exemplary formillustrated is incorporated in a tool .handle which comprises a main orunitary tubular casing 1 having a passage 2 therethrough. As viewed inFigures 1 and 2 the governor is positioned at the left hand or tool endof the handle7 and valve means manually operable to control theV flow ofpressure fluid through the passage is carried at the right hand orintake end.

The manually operable'valve means com prises a cylindrical sleeve 8mounted in the outerend of the casing 1, being secured therein by apress lit 3a and against a shoulder 4 in the casing to prevent movementof the sleeve inwardly. The outer-end of the sleeve is preferablybeveled as at 5 to provide a valve seat. Slidfable Within the sleeve isa cylindrically shaped member 6, carrying on oneV end thereofa valve 7adapted to engage said seat to close the passage 2. This cylindricalmember has an annular groove S im` mediatelybehind said valve andlongitudinal ducts 9 leading from said groove to the inner end of themember,

Means is provided to permit of manual reciprocation of the cylindricalmember 6 to open and close the passage 2. This means comprises a pin 11secured to the valve membertA and Vextending radially therefrom througha longitudinal guide slot 12 in the sleeve 3 in the casing 1, and alnurled sleeve 13 mounted for partial rotation on a slightly reducedportion le of the said casing. This sleeve is retained on the casingbetween a shoulder 15 formed in the casing and a flange 16 on a couplingmember 17 in screw-threaded engagement With the end of the casing7 andhas a spirally formed slot 18 ther-ein as shown in Fig'. 1'. This slot18is adapted also to admit the pin l1` so lthat upon rotation of thesleeve 13 the pin 11 is moved longitudinallyv in the guide slot 12. Thevalve 7 carried by the member 6 moves with the pin 11 longitudinallyofthe casing and is thereby4 operated to open orclose the passage 2.

The automatic governing means as herein disclosed cooperat'esfvvith the"above'V described man ual'lyoperable valve'to regulate the flow' of-vpressufr'e Y flu-id through the handle and is positioned in the casing 1between the manually operable valve and a tool (not shown). Asillustrated, this governing means comprises an inner casing or tube 19having a transverse wall 2O closing one end thereof and an annular'flange 21 projecting radially outward at the opposite end. The tube 19is secured detachably in the main casing 1, the flange 21 being hereinshown clamped between the end of the casing and a shoulder 22 of acoupling member 23 screw-threaded on the casing. The tube is preferablypositioned centrally of the casing.

A bushing 24 (Figs. 2 and 5) is mounted for longitudinal adjustment inthe open end of the tube 19 by suitable means such as the screw-threads25, kerfs 26 being provided therein for engagement by a suitable tool toobtain such adjustment manually. This valve bushing, as shown clearly inFig. 5 has an axial bore 27, and is cut away at diametrically oppositesides so as to form two spaced annular collars 28 and 29 joined by oneor more bars 30. These bars form side wall ports 32 intermediate saidcollars and are reduced in thickness to form annular shoulders 31surrounding the bore 27 on the adjacent sides of the collars. Thebushing is adapted to be positioned in the tube 19 with the ports 32adjacent a plurality of ports 33 in the side wall of the tube.

Centrally within the tube 19 is positioned al tubular metallic bellows34 which is adapted to expand and contract longitudinally with thedecrease and increase of pressure within the tube, (the corrugationsherein sho-wn being on an enlarged scale for purposes of illustration).This bellows is made of a maximum external diameter less than theinternal diameter of the tube 19 and is sealed at both ends. A plug 35which closes the inner end of the tubular bellows is suitably secured tothe end wall 2O of the tube 19 and axially thereof, as, for example, bymeans of a threaded portion of the plug extending through a hole in thewall 20 and engaging a nut 36. Closing the other end of the tubularbellows and carried thereby is a cylindrical cup-shaped valve 37 adaptedto slide freely within the valve bushing 24 to open and close the ports32 upon contraction and expansion of the bellows. Thus this valve 37 isadapted to control the flow of pressure fluid through the ports 32. v

Heretofore difficulty has been experienced in automatically operatedvalves of this general type with the valve fluttering or chattering asit opens. I have effectively overcome this fluttering movement by means.which in the preferred embodiment illustrated comprises a spirallyformed free end 38 on the side wall 39 of the valve. This asymmetricalformation permits the pressure fluid to exert a slight side pressure onthe valve by 'exposing a greater surface'at one side ofthe valve.

This side pressure reduces greatly the tendency of the freely slidablevalve to flutter.

The valve 37 is also provided with one or more apertures 40 therethroughpreferably at the. base of the side wall 39 to admit conl stantly, theback pressure fluid in the bore 41 of the valve to the tube 19 toactuate the bellows. Thus I provide a balanced valve which does not movewith or against the pressure vfluid, but -w-hose movements are governedpractically exclusively by the action of the pressure fluid on thebellows.

Assuming a supplyof pressure Vfluid at the right or intake end of thehandle as viewed in F ig. 2 and a tool to befoperated connected to thecoupling 23 at the opposite end, the operation of the preferred form ofthe invention is as follows:

Manual rotation of the knurled sleeve 13 in a clockwise direction asviewed from the intake end actuates the valve 7 to open the passage 2.Pressure fluid then flows throughthe passage`2 of the handle through theapertures 33 to the ports 32. Normally the bushing 24 is adjusted sothat the valve 37 closes all but a very small portion of the ports 32,this small opening being of sufficient size to pass enough pressurefluid to the tool to operate' the tool at a predetermined running lightor idling speed. As the valve 37 is not an airl tight fit in the bore 27of the bushing 24 but is adapted to slide freely therein to-preventsticking, any leakage past the valve is also utilized in operating thetool.

As the pressure required to operate a tool under such conditions is verylow, the pressure beyond the valve 37l and at the tool is comparativelylow. This low pressure fluid also enters through the apertures 40 intothe bellows chamber within thetube 19 but is insufiicient to compressthe metallic bellows. Tf then a load is applied to the tool, the toolslows down and theback pressure on the teol side of the port 32 and inthe bellows chamber within the tube 19 builds up. As this back pressureincreases the bellows 34 is contracted to withdraw the valve 37 andthereby permit increasing quantities of pressure fluid to flow throughthe port 32 to the tool.. If the load be removed from the tool thepressure on the tool side of the port 32 drops, with the result that thebellows expands and moves the valve to close the port. Similarly if thesleeve'13 be rotated to close the passage 2, the flow of pressure Huidis cut off and the valve 37 assumes its normal position.

From the foregoing, it will be apparent that I have provided an improvedgovernor l adapted to be mounted in thehandle of a pressure fluidoperated tool, the handle being of a size readily gripped by anoperator. The invention in the form disclosed is compact and of lightweight, features of particular advantage in portable tools of the typecontemplated, and its unitary construction adapts it for readydetachment for purposes of inspection, adjustment or repair.

I claim as my invention:

. l. A device of the character described having, in combination, atubular casing comprising two sections detachably secured together andhaving a pressure fluid passage therethrough, and a governing devicedisposed within said casing comprising a tube closed at one end andhaving at its opposite end an external peripheral flange adapted to beclamped between said casing sections, a bushing mounted for longitudinaladjustment adjacent the open end of said tube, said tube and bushinghaving a side wall port intermediate said flange and the closed end ofthe tube, a longitudinally compressible metallic device within said tubehaving one end thereof secured to said tube and having its opposite endfree, a valve carried on said free end of said metallic device andadapted to slide longitudinally in said bushing to control the flow ofpressure fluid through said port, and means to admit pressure fluid fromthe tool side of said port to actuate said compressible device.

2. A device of the character described comprising, in combination, ahollow cylindrical casing having a pressure fluid passage therethrough,a coupling member screw threaded to one end thereof and adapted toconnect said casing to a tool, a tube closed at one end and having atits other end an external annular flange adapted to be clamped betweenthe end of said casing and said coupling member, said tube having a portin its side wall forming a part of said passage, a cylindrically formedvalve member freely slidable in said tube and adapted to control saidport, means to adjust the normal position of said valve relative to saidport, a sealed tubular metallic bellows disposed in said tube with oneend secured therein and the other carrying said valve member, and meansto permit pressure fluid to actuate said bellows.

A governor' of the character described comprising, in combination, atubular casing, a bushing disposed within said casing and having anexternal annular portion abutting the inner peripheral wall of saidcasing, said bus-hing also having a side wall port adapted ,t'o form aportion of a pressure fluid passage through said casing, a valveasymmetrically formed relatively to said port and freely slidablelongitudinally in said bushing to control said port, and pressure fluidresponsive means to actuate said valve, said valve being suficientlyfree in said bore so that the pressure fluid operating on theasymmetrioally formed valve presses it to one side fwthe bore andnormally permits a small amount of fluid to leal( past the valve.

4.' A handle for pressure fluid operated tools comprising, incombination, a unitary tubular casing of a diameter adapted to begripped readily andl having a pressure fluid supply passagetherethrough, a coupling d evice secured to one end of said casing, saidcoupling device being adapted to be attached to pressure fluid operatedtool, a tube disposed longitudinally within said casing, said tubebeing` closed at one end and having at the other end an external annularLlange adapted to be clamped between said coupling device and ktheadjacent end of said casing, said tube also having a port therethroughadjacent said flange, Va compressible metallic bellows disposed withinsaid tube, one end of'said bellows being secured to said tube at itsclosed end, the other end of said bellows carrying a valve adapted tocontrol the flow of pressure fluid through said part, and means topermit pressure fluid from the tool side of said port to enter said tubeto actuate said bellows.

A governing device comprising, in combination, tubular casing closed atone end and of a diameter adapted toy be inserted in and to define aportion of the pressure fluid sup-ply passage in a handle for pressurefluid operated tools, said casing having adjacent its open end, a sidewall port and an internal annular groove connecting with said port, acup shaped valve, freely slidable longitudinally within said casingacross said groove, means to actuate said valve comprising a sealedcompressible metallic device disposed within said casing with one endsecured thereto and the opposite end carrying said valve, and means toadjust the normal position of said valve relative to said port.

6. A governor of the character described comprising, in combination, atubular casing closed at one end and adapted to fit detachably in thepressure fluid passage of a control handle for a pressure fluid operatedtool, said casing having adjacent its open end a bushing mounted thereinfor longitudinal adjustment, said bushing and casing having connectingside wall ports adapted to define a portion of the said passage, a valveslidable in said bushing to control said bushing port, a tubularmetallic bellows disposed within said casing with one end securedthereto and the other end carrying said valve, and means to admitpressure fluid from the tool side of said bushing port to actuate saidmetallic bellows.

7. In a pressure fluid governing device of the character described forportable tools, in combination, a tubular bushing providing a peripheralsymmetrical port defining a portion of a pressure fluid passage throughsaid device, a hollow cylindrical valve member freely slidable in saidbushing to control the flow of pressure fluid through said port, saidvalve member having a spirally formed end so that in the operation ofthe device the said valve member effects a gradual opening and closingof the port and pressure fluid Cil.

operated means to operate said valve member. 8. A governor of thecharacter described comprising, in combination, a easing having apressure Huid passage therethrough and valve means to control the flowof pressure l'luid through said passage, said valve means comprising avalve bushing having a cylindrical bore and a side Wall port defining aportion of said passage, a cylindrical valve asymmetrically formedrelatively to said port and freely slidable in said bore, and pressureresponsive means adapted to aotuate said valve to Control the flow ofpressure fluid through said port, said valve being suflieiently free insaid bore so that the pressure Huid operating on the asymmetrieallyformed valvepresses it to one side of the bore and normally permits asmall amount of Huid to leak past the valve.

9. governor of the Character described comprising, in Combination, anouter casing, an inner casing, a valve bushing adjustahly7 mounted inthe inner easing having a side Wall annular port in communication withthe outer easing, a valve controlling said port slidable freely in saidbushing, and means in Said inner easing supporting said valve operableon hack pressure fluid to aetuate said valve.

In testimony whereof, I have hereunto affixed my signature.

ERNEST H. SHAFF.

